Should a mother's will to dedicate her two houses as a waqf for the needy among her children after her death be carried out, and would the second floor, which the sister built with her own money in one of the two houses, also be considered part of the waqf?

A father is permitted to designate an endowment (waqf) for one of his children if that child has needs not shared by their siblings. If a mother bequeaths a third or less of her wealth to someone who is not an heir, the bequest (wasiyya) is unanimously considered permissible. However, a bequest to an heir is not permissible unless the other heirs approve it, and they must be mature and adult, based on the hadith (definition): "There is no bequest for an heir." It is advisable to refer matters of inheritance to Sharia (definition) courts due to the presence of bequests, debts, or rights that take precedence over the rights of the heirs.